This invention relates generally to power delivery systems for microelectronic circuits, and more particularly to methods and apparatuses for supplying power to such devices through a capacitor DC shunt.
As the frequencies of microprocessors increase, the currents supplied through sockets required to power these devices increases proportionally. One method used to manufacture devices operating at increased frequencies is to reduce the size of the device using improved lithographic techniques. Accordingly, while the magnitude of the current increases, the amount of area used to carry the current through the socket is decreased. High currents through sockets require low resistances in order to have small power dissipation. This relationship is described by the equation: P=I2R (Power=Current squared times the Resistance). Larger power dissipations in the socket result in higher temperatures in the socket, and higher temperatures are known to cause problems with the operational reliability of the microprocessor. Judging by current trends in microprocessor design, the anticipated maximum current required to power designs in the near future will exceed socket limitations by 20%˜30%.
One method for increasing currents through sockets to supply the high currents to higher power CPU's is currently solved by increasing the number of pins. Increasing the number of power supply pins lowers the total resistance and results in a lower power dissipation. This is costly not only in terms of actual dollar cost for the extra pins, but also for the chip real estate needed for the extra pins. In addition, if the number of pins added for power dissipation does not provide a much lower resistance than the resistance of the pins in the core region, the effectiveness of the additional pins may not sufficiently reduce the current flowing through one region of the package. In other words, additional pins must provide an effective DC shunt.
Accordingly, the need remains for an alternate method for supplying current to microprocessors of ever-decreasing dimensions.